The way I see it, we have two core issues at hand with email and privacy. 1) The NSA is intercepting email in transit and/or 2) They are obtaining access to where ever the email records are stored via legal or non legal means.
My solution is a local application installed on the computer itself used for email functions, similar to that of Outlook or Thunderbird. Except with no centralized server for transmitting or storage. Instead store all communication logs and copies locally on the clients computer. Along with encryption certs unique to each persons computer. When generating your certs, you would generate with a specific person in mind, so that when you put in parameters for generating a new, unique key, the other person that you are wanting to communicate with can create a corresponding cert that will decrypt the message upon arrival.
One problem I have already is to have keys that reflect the ability for each persons client to read each persons emails. How do you share something you want to keep secret, to keep things secret, without exposing the keys to flaws.
Anyway, moving on, the actual trick I have come up with though is splitting. I want to send an email to person B, so I type it up, I hit a button that says "prepare to send" which sets into action a few steps. One, it fills the email with random crap that doesnt matter to make it larger. Two, it splits this new, larger email, into say, 20 smaller files, but in random splits that will have to be remerged once it has been received. Because it has been split into pieces, we will also want to send each piece through a different transit server before it hits its destination. In this way, even if the emails get caught in a dragnet, or are even targeted, they would have to be lucky enough to get all 20 pieces, know how to decrypt them, put them back together, and get rid of the BS that was filled into them. With them split and going in different ways before going to the same place, and the gov entity not knowing how many pieces there were, they wont even know how many they are looking for.
So
Message - process - FILL with random (Im thinking this is more like salting if im not mistaken).
Split into x number of emails
Send through multiple servers so not as easily obtained, tracked, or pieced together.
Received by the recipient software that can reassemble, take out the BS, and decypher the encryption locally.
None of it ever stored anywhere but the 2 persons computers.
When I say fill with bs, I mean like you typed-
Dear John,
Marry had a little lamb. Daddy killed it dead. Marry took it to school next day between two pieces of bread.
Love
Bob
You take this and add characters all throughout the email, jumbling the sentences before the messages themselves are even encrypted by some other standard means. And before that standard method is used, the email has been shattered into many many emails of random number before you even wrap it up to be used for transit.
Sorry for the wall of text and probably repeating myself, but I am trying to be thorough in my explanation so as to prevent misunderstandings. I am also typing in a hurry because I have to leave the lab and wont be on for a little while.
Anyway, Im just throwing it out there. Thanks.